<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <!-- 只读 -->
    <div>
        <input type="text" placeholder="用户名" value="tom" readonly>
        <input type="text" placeholder="用户名" value="tom" readonly="readonly">
        <input type="text" placeholder="用户名" value="tom" readonly="true">
    </div>
    <!-- 禁用 -->
    <div>
        <input type="text" placeholder="用户名" value="tom" disabled>
        <input type="text" placeholder="用户名" value="tom" disabled="disabled">
        <input type="text" placeholder="用户名" value="tom" disabled="true">
    </div>
    <div>
        <input type="checkbox" name="sports" value="1" checked> 足球        
        <input type="checkbox" name="sports" value="2" checked="checked"> 篮球        
        <input type="checkbox" name="sports" value="3" checked="true"> 排球        
        <input type="checkbox" name="sports" value="4"> 台球   
        <input type="radio" name="gender" value="0"> 男
        <input type="radio" name="gender" checked value="1"> 女
    </div>
</body>
</html>